Si-containing film forming precursors and methods of using the same

ABSTRACT

Methods are disclosed for forming a Silicon Metal Oxide film using a mono-substituted TSA precursor. The precursors have the formula: (SiH3)2N—SiH2-X, wherein X is selected from a halogen atom; an isocyanato group; an amino group; an N-containing C4-C10 saturated or unsaturated heterocycle; or an alkoxy group.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/513,307, filed Jul. 16, 2019, which is a continuation ofU.S. patent application Ser. No. 15/693,544, filed Aug. 31, 2017 andissued as U.S. Pat. No. 10,403,494 on Sep. 3, 2019, which is acontinuation of U.S. patent application Ser. No. 14/738,039, filed Jun.12, 2015 and issued as U.S. Pat. No. 9,777,025 on Oct. 3, 2017, whichclaims the benefit of U.S. Provisional Application No. 62/140,248, filedMar. 30, 2015, herein incorporated by reference in its entirety for allpurposes.

TECHNICAL FIELD

Disclosed are Si-containing film forming compositions comprisingmono-substituted trisilylamine precursors, methods of synthesizing thesame, and methods of using the same to deposit Si-containing films usingvapor deposition processes for manufacturing semiconductors,photovoltaics, LCD-TFT, flat panel-type devices, refractory materials,or aeronautics.

BACKGROUND

A variety of silicon containing precursor have been used to depositSi-containing thin films on various substrates by vapor depositionprocesses. The choice of the suitable silicon precursor and, whenapplicable, of the co-reactant are generally driven by the target filmcomposition and properties, as well as by the constraints brought by thesubstrate on which the film is to be deposited. Some substrates mayrequire low temperature deposition processes. For instance, depositionon plastic substrates or Si substrates coated with organic films mayrequire deposition temperatures below 100° C. (i.e., 20° C.-100° C.),while maintaining a reasonable deposition rate to be of industrialinterest. Such films may be used as spacer-defined lithographyapplication in semiconductor fabrication, but also for sealing organiclight-emitting diode (OLED) devices or creating moisture diffusionbarriers on films. Similar constraints at different temperature rangesappear in the different steps of semiconductor manufacturing, such as,capping layers over metals, gate spacers, etc.

Trisilylamine (TSA) is a molecule with a high Si content and has theformula of N(SiH₃)₃. TSA may be used as a low temperature (T) siliconnitride precursor (see, e.g., U.S. Pat. No. 7,192,626), as well as aprecursor for flowable CVD (see, e.g., U.S. Pat. No. 8,846,536, US2014/0057458 or U.S. Pat. No. 8,318,584). However, while TSA appears asa versatile precursor (Carbon-free and low T capability) for a varietyof thin film deposition processes, it's applicability to thermal ALD hasbeen limited (see, e.g., U.S. Pat. No. 8,173,554, indicating that plasmaactivation is necessary to obtain a meaningful growth per cycle).

US2014/0363985 A1 discloses amino-silylamines used for forming asilicon-containing thin-film having a generic formula ofR¹R²R³Si—N(SiR⁴R⁵—NR⁶R⁷)₂, wherein R¹ to R⁵ are each independentlyhydrogen, halogen, (C1-C7)alkyl, (C2-C7)alkenyl, (C2-C7)alkynyl,(C3-C7)cycloalkyl or (C6-C12)aryl. US2014/0158580A describes analkoxysilylamine having a TSA-like structure. U.S. Pat. No. 7,122,222uses a Si—C bond free hydrazinosilane precursor [R¹₂N—NH]_(n)Si(R²)_(4-n)] to deposit SiN, SiO₂ and SiON films. Silazanecompounds N—(SiR¹R²R³)_(m)R⁴ _(3-m) disclosed in WO2013/058061 are usedas a coating gas. (RR¹R²M^(a))_(y)A(R³)_(x) disclosed in U.S. Pat. No.5,332,853 is used as a catalytic compound to produce a functionalizedalkylalkali metal compound. Similar patents include U.S. Pat. Nos.5,663,398A, 5,332,853A, 5,340,507A, EP 525881 A1, etc.

As such, industries using vapor-based deposition processes such as CVDor ALD (in all possible meanings, such as LPCVD, SACVD, PECVD, PEALD,etc.) are still looking for precursors that are ideal for theirapplications, i.e. having the highest possible deposition rates withinthe constraints of their processes, substrates and film targets.

SUMMARY

Disclosed are Si-containing film forming compositions comprising amono-substituted TSA precursor having the formula (SiH₃)₂NSiH₂—X,wherein X is a halogen atom selected from Cl, Br or I; an isocyanatogroup [—NCO]; an amino group [—NR¹R²]; a N-containing C4-C10 saturatedor unsaturated heterocycle; or an alkoxy group [—O—R]; R¹, R² and R isselected from H; a silyl group [—SiR′₃]; or a C₁-C₆ linear or branched,saturated or unsaturated hydrocarbyl group; with each R′ beingindependently selected from H; a halogen atom selected from Cl, Br, orI; a C₁-C₄ saturated or unsaturated hydrocarbyl group; a C₁-C₄ saturatedor unsaturated alkoxy group; or an amino group [—NR³R⁴] with each R³ andR⁴ being independently selected from H and a C₁-C₅ linear or branched,saturated or unsaturated hydrocarbyl group, provided that if R¹═H, thenR²≠H, Me or Et. The disclosed Si-containing film forming compositionsmay include one or more of the following aspects:

-   -   the mono-substituted TSA precursor wherein X is a halogen atom;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—Cl;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—Br;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—I;    -   the mono-substituted TSA precursor wherein X is a isocyanate        —NCO (i.e., being (SiH₃)₂N—SiH₂—NCO);    -   the mono-substituted TSA precursor wherein X is an amino group        [—NR¹R²];    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—NiPr₂;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—NHiPr;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—NHtBu;    -   the mono-substituted TSA precursor not being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NHEt)) (i.e., when X═NR¹R² and R¹ is        SiH₃ and R² is NHEt);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂ NEt₂;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂ NEtMe;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂ NMe₂;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂ NMeiPr;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂ NEtiPr    -   the mono-substituted TSA precursor wherein X is —N(SiR₃)₂,        wherein each R is independently selected from a halogen, H, or a        C₁-C₄ alkyl group;    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂—N(SiCl₃)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂—N(SiBr₃)₂;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—N(SiI₃)₂;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—N(SiH₃)₂    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂C);    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NEt₂);    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NiPr₂);    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NHtBu);    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂OEt);    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂OiPr);    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂—N(SiMe₃)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂—NH(SiMe₃);    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂—N(SiEt₃)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiMe₂Et)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiMe₂iPr)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiMe₂nPr)₂;    -   the mono-substituted TSA precursor wherein X is a N-containing        C₄-C₁₀ heterocycle;    -   the mono-substituted TSA precursor wherein the N-containing        C₄-C₁₀ heterocycle is selected from pyrrolidine, pyrrole, and        piperidine;    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂-(pyrrolidine);    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂-(pyrrole);    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂-(piperidine)    -   the mono-substituted TSA precursor wherein X is an alkoxy group        [—O—R];    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OH);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OMe);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OEt);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OiPr);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OnPr);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OtBu);    -   the mono-substituted TSA precursor wherein X is —O—SiR₃ and each        R is independently selected from H, a halogen, or a C₁-C₄        hydrocarbyl group;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OSiH₃);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OSiCl₃);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OSiBr₃);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OSiI₃);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OSiMe₃);    -   the Si-containing film forming composition comprising between        approximately 95% w/w and approximately 100% w/w of the        precursor;    -   the Si-containing film forming composition comprising between        approximately 5% w/w and approximately 50% w/w of the precursor;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Al;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw As;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Ba;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Be;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Bi;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Cd;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Ca;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Cr;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Co;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Cu;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Ga;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Ge;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Hf;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Zr;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw In;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Fe;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Pb;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Li;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Mg;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Mn;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw W;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Ni;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw K;    -   the o Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Na;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Sr;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Th;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Sn;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Ti;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw U;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw V;    -   the Si-containing film forming composition comprising between        approximately 0 ppbw and approximately 500 ppbw Zn;    -   the Si-containing film forming organosilane composition        comprising between approximately 0 ppmw and approximately 500        ppmw Cl;    -   the Si-containing film forming composition comprising between        approximately 0 ppmw and approximately 500 ppmw Br;    -   the Si-containing film forming composition comprising between        approximately 0 ppmw and approximately 500 ppmw I;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w TSA;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w (SiH₃)₂—N—SiH₂X, wherein X        is Cl, Br, or I;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w (SiH₃)₂—N—SiHX₂, wherein X        is Cl, Br, or I;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w SiH₄;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w SiH₃X, wherein X is Cl, Br,        or I;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w SiH₂X₂, wherein X is Cl, Br,        or I;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w SnX₂, wherein X is Cl, Br,        or I;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w SnX₄, wherein X is Cl, Br,        or I;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w HX, wherein X is Cl, Br, or        I;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w NH₃;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w NH₄X, wherein X is Cl, Br,        or I;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w ROH, wherein R is C1-C4        alkyl group;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w NH₂R, wherein R is a C1-C4        alkyl group;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w NR₂H, wherein R is a C1-C4        alkyl group;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w HN═R, wherein R is a C1-C4        alkyl group;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w tetrahydrofuran (THF);    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w ether;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w pentane;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w cyclohexane;    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w heptane; or    -   the Si-containing film forming composition comprising between        approximately 0.0% w/w and 0.1% w/w toluene.

Also disclosed are methods of depositing a Si-containing layer on asubstrate. The composition disclosed above is introduced into a reactorhaving a substrate disposed therein. At least part of themono-substituted TSA precursor is deposited onto the substrate to formthe Si-containing layer using a vapor deposition method. The disclosedmethods may have one or more of the following aspects:

-   -   introducing into the reactor a vapor comprising a second        precursor;    -   an element of the second precursor being selected from the group        consisting of group 2, group 13, group 14, transition metal,        lanthanides, and combinations thereof;    -   the element of the second precursor being selected from As, B,        P, Si, Ge, Al, Zr, Hf, Ti, Nb, Ta, or lanthanides;    -   introducing a reactant into the reactor;    -   the reactant being selected from the group consisting of O₂, O₃,        H₂O, H₂O₂, NO, NO₂, a carboxylic acid, an alcohol, a diol,        radicals thereof, and combinations thereof;    -   the reactant being plasma treated oxygen;    -   the Si-containing layer being a silicon oxide containing layer;    -   the reactant being selected from the group consisting of N₂, H₂,        NH₃, hydrazines (such as N₂H₄, MeHNNH₂, MeHNNHMe), organic        amines (such as NMeH₂, NEtH₂, NMe₂H, NEt₂H, NMe₃, NEt₃,        (SiMe₃)₂NH), pyrazoline, pyridine, diamines (such as ethylene        diamine), radical species thereof, and mixtures thereof;    -   the vapor deposition method being a chemical vapor deposition        process;    -   the vapor deposition method being an ALD process;    -   the vapor deposition method being a spatial ALD process;    -   the vapor deposition process being a flowable CVD process;    -   the silicon-containing layer being Si;    -   the silicon-containing layer being SiO₂;    -   the silicon-containing layer being SiN;    -   the silicon-containing layer being SiON;    -   the silicon-containing layer being SiOC;    -   the silicon-containing layer being SiOCN;    -   the silicon-containing layer being SiCN;    -   thermal annealing the Si-containing layer;    -   thermal annealing the Si-containing layer under a reactive        atmosphere;    -   UV curing the Si-containing layer; and    -   Electron beam curing the Si-containing layer.

Also disclosed are nitrogen-doped silicon oxide films formed by theprocess of introducing into a reactor containing a substrate a vaporincluding a mono-substituted TSA precursor to form a silicon-containinglayer on the substrate; reacting an oxidizing agent with thesilicon-containing layer to form an oxidized silicon-containing layer byintroducing the oxidizing agent into the reactor; reacting themono-substituted TSA precursor with the oxidized silicon-containinglayer to form a silicon-rich oxidized silicon-containing layer byintroducing the mono-substituted TSA precursor into the reactor; andreacting a nitrogen-containing reactant with the silicon-containinglayer to form the nitrogen-doped silicon oxide film by introducing thenitrogen-containing reactant into the reactor. The mono-substituted TSAprecursors have a formula (SiH₃)₂N—SiH₂—X, wherein X is selected from ahalogen atom selected from Cl, Br or I; an isocyanato group [—NCO]; anamino group [—NR¹R²]; a N-containing C₄-C₁₀ saturated or unsaturatedheterocycle; or an alkoxy group [—O—R]; R¹, R² and R each is selectedfrom H; a C₁-C₆ linear or branched, saturated or unsaturated hydrocarbylgroup; or a silyl group SiR′₃ with each R′ being independently selectedfrom H; a halogen atom selected from Cl, Br, or I; a C₁-C₄ saturated orunsaturated hydrocarbyl group; a C₁-C₄ saturated or unsaturated alkoxygroup; or an amino group —NR³R⁴ with each R³ and R⁴ being selected fromH or a C₁-C₆ linear or branched, saturated or unsaturated hydrocarbylgroup, provided that if R¹═H, then R²≠H or Me. The process to producethe disclosed nitrogen-doped silicon oxide films may include one or moreof the following aspects:

-   -   purging the reactor with an inert gas between each introduction        step;    -   the mono-substituted TSA precursor wherein X is a halogen atom;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—Cl;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—Br;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—;    -   the mono-substituted TSA precursor wherein X is a isocyanate        —NCO (i.e., being (SiH₃)₂N—SiH₂—NCO);    -   the mono-substituted TSA precursor wherein X is an amino group        [—NR¹R²];    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—NiPr₂;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—NHiPr;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—NHtBu;    -   the mono-substituted TSA precursor not being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NHEt)) (i.e., when X═NR¹R² and R¹ is        SiH₃ and R² is NHEt);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂-NEt₂;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂ NEtMe;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂ NMe₂;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂ NMeiPr;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂ NEtiPr;    -   the mono-substituted TSA precursor wherein X is —N(SiR₃)₂,        wherein each R is independently selected from a halogen, H, or a        C₁-C₄ alkyl group;    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂—N(SiCl₃)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂—N(SiBr₃)₂;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—N(SiI₃)₂;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—N(SiH₃)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂C);    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NEt₂);    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NiPr₂);    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NHtBu);    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂OEt);    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂OiPr);    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂—N(SiMe₃)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂—NH(SiMe₃);    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂—N(SiEt₃)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiMe₂Et)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiMe₂iPr)₂;    -   the mono-substituted TSA precursor being        (SiH₃)₂—N—SiH₂—N(SiMe₂nPr)₂;    -   the mono-substituted TSA precursor wherein X is a N-containing        C₄-C₁₀ heterocycle;    -   the mono-substituted TSA precursor wherein the N-containing        C₄-C₁₀ heterocycle is selected from pyrrolidine, pyrrole, and        piperidine;    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂-(pyrrolidine);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂-(pyrrole)    -   the mono-substituted TSA precursor being        (SiH₃)₂N—SiH₂-(piperidine);    -   the mono-substituted TSA precursor wherein X is an alkoxy group        [—O—R];    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OH);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OMe);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OEt);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OiPr);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OnPr);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OtBu);    -   the mono-substituted TSA precursor wherein X is —O—SiR₃ and each        R is independently selected from H, a halogen, or a C₁-C₄        hydrocarbyl group;    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OSiH₃);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OSiCl₃);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OSiBr₃);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OSiI₃);    -   the mono-substituted TSA precursor being (SiH₃)₂N—SiH₂—(OSiMe₃),        the reactant being selected from the group consisting of O₂, O₃,        H₂O, H₂O₂, NO, NO₂, a carboxylic acid, an alcohol, a diol,        radicals thereof, and combinations thereof; and    -   the reactant being selected from the group consisting of N₂, H₂,        NH₃, hydrazines (such as N₂H₄, MeHNNH₂, MeHNNHMe), organic        amines (such as NMeH₂, NEtH₂, NMe₂H, NEt₂H, NMe₃, NEt₃,        (SiMe₃)₂NH), pyrazoline, pyridine, diamines (such as ethylene        diamine), radical species thereof, and mixtures thereof.

Notation and Nomenclature

The following detailed description and claims utilize a number ofabbreviations, symbols, and terms, which are generally well known in theart. While definitions are typically provided with the first instance ofeach acronym, for convenience, Table 1 provides a list of theabbreviations, symbols, and terms used along with their respectivedefinitions.

TABLE 1 a or an One or more than one Approximately ±10% of the valuestated or about LCD-TFT liquid-crystal display-thin-film transistor MIMMetal-insulator-metal DRAM dynamic random-access memory FeRamFerroelectric random-access memory OLED organic light-emitting diode CVDchemical vapor deposition LPCVD low pressure chemical vapor depositionPCVD pulsed chemical vapor deposition SACVD sub-atmospheric chemicalvapor deposition PECVD plasma enhanced chemical vapor deposition APCVDatmospheric pressure chemical vapor deposition HWCVD hot-wire chemicalvapor deposition FCVD flowable chemical vapor deposition MOCVD metalorganic chemical vapor deposition ALD atomic layer deposition spatialALD spatial atomic layer deposition HWALD hot-wire atomic layerdeposition PEALD plasma enhanced atomic layer deposition sccm standardcubic centimeters per minute MP melting point TGA thermogravimetricanalysis SDTA simultaneous differential thermal analysis GCMS gaschromatography-mass spectrometry TSA trisilylamine SRO strontiumruthenium oxide HCDS hexachlorodisilane PCDS pentachlorodisilane OCTSn-octyltrimethoxysilane MCS monochlorosilane DCS dichlorosilane TSATrisilylamine DSA disilylamine TriDMAS or tris(dimethylamino)silane orSiH(NMe₂)₃ TDMAS BDMAS bis(dimethylamino)silane or SiH₂(NMe₂)₂ BDEASbis(diethylamino)silane or SiH₂(NEt₂)₂ TDEAS tris(diethylamino)silane orSiH(NEt₂)₃ TEMAS tris(ethylmethylamino)silane or SiH(NEtMe)₃ TMAtrimethyl aluminum or AlMe₃ PET polyethylene terephthalate TBTDEN(tert-butylimido)bis(dimethylamino)niobium or Nb(═NtBu)(NMe₂)₂ PENpolyethylene naphthalate PEDOT:PSS poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) Alkyl group saturatedfunctional groups containing exclusively carbon and hydrogen atoms,including linear, branched, or cyclic alkyl groups Me Methyl Et EthyliPr aryl aromatic ring compounds where one hydrogen atom has beenremoved from the ring heterocycle cyclic compounds that has atoms of atleast two different elements as members of its ring PTFEPolytetrafluoroethylene

The standard abbreviations of the elements from the periodic table ofelements are used herein. It should be understood that elements may bereferred to by these abbreviations (e.g., Si refers to silicon, N refersto nitrogen, O refers to oxygen, C refers to carbon, etc.).

As used herein, the term “independently” when used in the context ofdescribing R groups should be understood to denote that the subject Rgroup is not only independently selected relative to other R groupsbearing the same or different subscripts or superscripts, but is alsoindependently selected relative to any additional species of that same Rgroup. For example in the formula MR¹ _(x) (NR²R³)_((4-x)), where x is 2or 3, the two or three R¹ groups may, but need not be identical to eachother or to R² or to R³. Further, it should be understood that unlessspecifically stated otherwise, values of R groups are independent ofeach other when used in different formulas.

BRIEF DESCRIPTION OF THE FIGURES

For a further understanding of the nature and objects of the presentinvention, reference should be made to the following detaileddescription, taken in conjunction with the accompanying figure wherein:

FIG. 1 is a diagram of the Picosun R200 PEALD 8″ deposition tool used toperform the depositions in Examples 4-6;

FIG. 2 is a graph the ALD growth rate of silicon oxide films as afunction of the number of precursor pulses using the precursor(SiH₃)₂N—SiH₂—NiPr₂;

FIG. 3 is a graph of the ALD growth rate of silicon oxide thin film as afunction of the temperature using the precursor (SiH₃)₂N—SiH₂—NiPr₂; and

FIG. 4 is a graph the ALD growth rate of silicon oxide films as afunction of the number of precursor pulses and the temperature using theprecursor (SiH₃)₂N—SiH₂—N(SiH₃)₂.

DESCRIPTION OF PREFERRED EMBODIMENTS

Disclosed are Si-containing film forming compositions comprisingmono-substituted TSA precursors having a Si—C bond free backbone and asingle chemically functionalized site to enable a high surfacereactivity. Mono-substituted TSA precursors having a number of siliconatoms higher than 1, and preferably higher than 2, without a direct Si—Cbond, and being polar molecules may have an enhanced reactivity to asubstrate surface to enable a fast deposition rate. The mono-substitutedTSA precursors have the general formula:(SiH₃)₂N—SiH₂—Xwherein X is selected from a halogen atom selected from Cl, Br or I; anisocyanato group [—NCO]; an amino group [—NR¹R²]; a N-containing C₄-C₁₀saturated or unsaturated heterocycle; or an alkoxy group —O—R; each R¹,R² and R selected from a H; a silyl group (SiR′₃); or a C₁-C₆ linear orbranched, saturated or unsaturated hydrocarbyl group; with each R′ beingindependently selected from H; a halogen atom selected from Cl, Br, orI; a C₁-C₄ saturated or unsaturated hydrocarbyl group; a C₁-C₄ saturatedor unsaturated alkoxy group; or an amino group [—NR³R⁴], with each R³and R⁴ being independently selected from H or a C₁-C₆ linear orbranched, saturated or unsaturated hydrocarbyl group; provided that ifR¹═H, then R²≠H, Me, or Et. The C₁-C₆ linear or branched, saturated orunsaturated hydrocarbyl group may contain amines or ethers.Alternatively, R¹ and R² may be independently selected from Me, Et, iPr,nPr, tBu, nBu, and secBu.

When X is a halide, exemplary Si-containing film forming compositionsinclude (SiH₃)₂—N—SiH₂Cl, (SiH₃)₂—N—SiH₂Br, or (SiH₃)₂—N—SiH₂I. Thesecompositions may be synthesized according to the reaction:SnX₄+N(SiH₃)₃→N(SiH₃)₂(SiH₂X)+SnX₂←+HXI, wherein X is Cl, Br, or I (seeJ. Chem. Soc. Dalton Trans. 1975, p. 1624). Alternatively, dihalosilane[SiH₂X₂, wherein X is C, Br, or I] and monohalosilane [SiH₃X, wherein Xis C, Br, or I] may be introduced continuously in the gas phase in a1/20 to ¼ ratio and at room temperature with 400 sccm of NH₃ in aflow-through tubular reactor as described by Miller in U.S. Pat. No.8,669,387. The reaction of NH₃ with 2 equivalents of monohalosilaneproduces mostly disilylamine (DSA). DSA then reacts with thedihalosilane to form (SiH₃)₂—N—SiH₂X and HX, wherein X is Cl, Br, or I.One of ordinary skill in the art would recognize that the reaction maytake place in one or two steps (first forming DSA from themonohalosilane and NH₃ and second adding dihalosilane) or in one step(combining the monohalosilane, dichlorosilane, and NH₃ in one step).

When X is an isocyanato group [—NCO], exemplary Si-containing filmforming compositions include (SiH₃)₂—N—SiH₂(NCO). This composition maybe synthesized using dehydrogenerative coupling according to the methoddisclosed by Taniguchi et al. in Angewandte Communications, Angew. Chem.Int. Ed. 2013, 52, 1-5, the teachings of which are incorporated hereinby reference. More particularly, (SiH₃)₃N may be reacted with urea(NH₂CONH₂) to form (SiH)₂—N—SiH₂(NCO)+H₂ in the presence of goldnanoparticles supported on alumina.

When X is an amino group [—NR¹R²], exemplary Si-containing film formingcompositions include (SiH₃)₂—N—SiH₂(NEt₂), (SiH₃)₂—N—SiH₂(NiPr₂),(SiH₃)₂—N—SiH₂(NHiPr), (SiH₃)₂—N—SiH₂(NHtBu), (SiH₃)₂—N—SiH₂[N(SiH₃)₂],(SiH₃)₂—N—SiH₂[N(SiH₃)(SiH₂Cl)], (SiH₃)₂—N—SiH₂[N(SiH₃)(SiH₂(NEt₂))],(SiH₃)₂—N—SiH₂[N(SiH₃)(SiH₂(NiPr₂))],(SiH₃)₂—N—SiH₂[N(SiH₃)(SiH₂(NHtBu))], (SiH₃)₂—N—SiH₂[N(SiH₃)(SiH₂OEt)],(SiH₃)₂—N—SiH₂[N(SiH₃)(SiH₂OiPr)], (SiH₃)₂—N—SiH₂[N(SiMe₃)₂],(SiH₃)₂—N—SiH₂[NH(SiMe₃)], (SiH₃)₂—N—SiH₂[N(SiEt₃)₂),(SiH₃)₂—N—SiH₂[N(SiMe₂Et)₂), (SiH₃)₂—N—SiH₂[N(SiMe₂iPr)₂),(SiH₃)₂—N—SiH₂[N(tBu)(SiH₃)), (SiH₃)₂—N—SiH₂[N(SiMe₂nPr)₂),(SiH₃)₂N—SiH₂ NEtMe, (SiH₃)₂N—SiH₂ NMe₂, (SiH₃)₂N—SiH₂ NMeiPr, or(SiH₃)₂N—SiH₂ NEtiPr.

The amino-substituted Si-containing film forming compositions may besynthesized similarly to the halo-substituted Si-containing film formingcompositions disclosed above. More particularly, 200 sccm ofmonohalosilane and 50 sccm of dihalosilane may be introducedcontinuously in the gas phase and at room temperature with 400 sccm ofNH₃ in a flow-through tubular reactor as described in U.S. Pat. No.8,669,387, forming a stream consisting of various silylamines andammonium halide, from which (SiH₃)₂—N—SiH₂[N(SiH)₂] may be isolated bymethods easily derived by a person having ordinary skill in the art,such as a method of fractional distillation.

More particularly, (SiH₃)₂—N—SiH₂[N(SiMe₃)₂] may be synthesized from thereaction of SiMe₃—NH—SiMe₃ with tBuLi→(Me₃Si)₂NLi, and reaction of(Me₃Si)₂NLi with (SiH₃)₂—N—SiH₂—Cl→(SiH₃)₂—N—SiH₂—N(SiMe₃)₂+LiCl).

Similarly, (SiH₃)₂—N—SiH₂—NH(SiMe₃) may be synthesized from the reactionof SiMe₃—NH—SiMe₃+(SiH₃)₂—N—SiH₂—Cl→(SiH₃)₂—N—SiH₂—NH-SiMea+Me₃SiCl.

(SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂X) may be synthesized from the reaction of(SiH₃)₂—N—SiH₂—N(SiH₃)₂ with SnX₃, wherein X is C, Br, or I (see J.Chem. Soc. Dalton Trans. 1975, p. 1624). Further substitution of(SiH₃)₂—N—SiH₂—N(SiH₃)₂ may be achieved by increasing the reaction timeand/or adjusting the stoichiometry.

(SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NEt₂)) may be synthesized from the reactionof (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂X) and HNEt₂. Further substitution of(SiH)₂—N—SiH₂—N(SiH₃)(SiH₂(NEt₂)) may be achieved by increasing thereaction time and/or adjusting the stoichiometry.

(SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NiPr₂)) may be synthesized from the reactionof (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂X) and HNiPr₂. Further substitution of(SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NiPr₂)) may be achieved by increasing thereaction time and/or adjusting the stoichiometry.

(SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NHtBu)) may be synthesized from the reactionof (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂X) and H₂NtBu. Please note that a similarreaction using H₂NEt may produce low yields of(SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(NHEt)).

(SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(OEt)) may be synthesized from the reactionof (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂X) and Ethanol (EtOH) in the presence of aHCl scavenger, like NEt₃ or pyridine.

(SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂(OiPr)) may be synthesized from the reactionof (SiH₃)₂—N—SiH₂—N(SiH₃)(SiH₂X) and isopropanol (PrOH) in the presenceof a HCl scavenger, like NEt₃ or pyridine.

When X is a N-containing C₄-C₁₀ saturated or unsaturated heterocycle,exemplary Si-containing film forming compositions include(SiH₃)₂—N—SiH₂-pyrrolidine, (SiH₃)₂—N—SiH₂-pyrrole, or(SiH₃)₂—N—SiH₂-piperidine. Alternatively, the N-containing C₄-C₁₀saturated or unsaturated heterocycle may also contain hetero-elements,such as P, B, As, Ge, and/or Si.

When X is an alkoxy group, exemplary Si-containing film formingcompositions include (SiH₃)₂—N—SiH₂(OEt), (SiH₃)₂—N—SiH₂(OiPr),(SiH₃)₂N—SiH₂—OSiMe₃, (SiH₃)₂—N—SiH₂—OSiMe₂OEt, or(SiH₃)₂—N—SiH₂—OSiHMe₂.

N(SiH₃)₂(SiH₂OEt) may also be synthesized from (SiH₃)₂—N—SiH₂Cl and EtOHin the presence of an acid scavenger, such as Et₃N or pyridine.N(SiH₃)₃+EtOH→N(SiH₃)₂(SiH₂OEt).

Preferably, the disclosed Si-containing film forming compositions havesuitable properties for vapor depositions methods, such as high vaporpressure, low melting point (preferably being in liquid form at roomtemperature), low sublimation point, and/or high thermal stability.

To ensure process reliability, the disclosed Si-containing film formingcompositions may be purified by continuous or fractional batchdistillation prior to use to a purity ranging from approximately 95% w/wto approximately 100% w/w, preferably ranging from approximately 98% w/wto approximately 100% w/w. One of ordinary skill in the art willrecognize that the purity may be determined by H NMR or gas or liquidchromatography with mass spectrometry. The Si-containing film formingcomposition may contain any of the following impurities: halides (X₂),trisilylamine, monohalotrisilylamine, dihalotrisilylamine, SiH₄, SiH₃X,SnX₂, SnX₄, HX, NH₃, NH₃X, monochlorosilane, dichlorosilane, alcohol,alkylamines, dialkylamines, alkylimines, THF, ether, pentane,cyclohexane, heptanes, or toluene, wherein X is Cl, Br, or I.Preferably, the total quantity of these impurities is below 0.1% w/w.The purified composition may be produced by recrystallisation,sublimation, distillation, and/or passing the gas or liquid through asuitable adsorbent, such as a 4A molecular sieve or a carbon-basedadsorbent (e.g., activated carbon).

The concentration of each solvent (such as THF, ether, pentane,cyclohexane, heptanes, and/or toluene), in the purified mono-substitutedTSA precursor composition may range from approximately 0% w/w toapproximately 5% w/w, preferably from approximately 0% w/w toapproximately 0.1% w/w. Solvents may be used in the precursorcomposition's synthesis. Separation of the solvents from the precursorcomposition may be difficult if both have similar boiling points.Cooling the mixture may produce solid precursor in liquid solvent, whichmay be separated by filtration. Vacuum distillation may also be used,provided the precursor composition is not heated above approximately itsdecomposition point.

The disclosed Si-containing film forming composition contains less than5% v/v, preferably less than 1% v/v, more preferably less than 0.1% v/v,and even more preferably less than 0.01% v/v of any of its mono-, dual-or tris-, analogs or other reaction products. This embodiment mayprovide better process repeatability. This embodiment may be produced bydistillation of the Si-containing film forming composition.

Purification of the disclosed Si-Containing film forming composition mayalso produce concentrations of trace metals and metalloids ranging fromapproximately 0 ppbw to approximately 500 ppbw, and more preferably fromapproximately 0 ppbw to approximately 100 ppbw. These metal or metalloidimpurities include, but are not limited to, Aluminum (Al), Arsenic (As),Barium (Ba), Beryllium (Be), Bismuth (Bi), Cadmium (Cd), Calcium (Ca),Chromium (Cr), Cobalt (Co), Copper (Cu), Gallium (Ga), Germanium (Ge),Hafnium (Hf), Zirconium (Zr), Indium (In), Iron (Fe), Lead (Pb), Lithium(Li), Magnesium (Mg), Manganese (Mn), Tungsten (W), Nickel (Ni),Potassium (K), Sodium (Na), Strontium (Sr), Thorium (Th), Tin (Sn),Titanium (Ti), Uranium (U), Vanadium (V) and Zinc (Zn). Theconcentration of X (where X═Cl, Br, I) in the purified mono-substitutedTSA precursor composition may range between approximately 0 ppmw andapproximately 100 ppmw and more preferably between approximately 0 ppmwto approximately 10 ppmw.

The disclosed Si-containing film forming compositions may be suitablefor the deposition of Si-containing films by various ALD or CVDprocesses and may have the following advantages:

-   -   liquid at room temperature or having a melting point lower than        50° C.;    -   thermally stable to enable proper distribution (gas phase or        direct liquid injection) without particles generation; and/or    -   suitable reactivity with the substrate to permit a wide        self-limited ALD window, allowing deposition of a variety of        Si-containing films.

Silicon nitride and silicon oxide containing films (referred to asSiO_(x)N_(y)) may be deposited by CVD or ALD using one or a combinationof reactants selected from the group comprising of N₂, H₂, NH₃, O₂, H₂O,H₂O₂, O₃, NO, NO₂, N₂O, a carboxylic acid, an alcohol, a diol,hydrazines (such as N₂H₄, MeHNNH₂, MeHNNHMe), organic amines (such asNMeH₂, NEtH₂, NMe₂H, NEt₂H, NMe₃, NEt₃, (SiMe₃)₂NH), pyrazoline,pyridine, diamines (such as ethylene diamine), a combination thereof,and the plasma product thereof.

Ternary or quaternary films may be deposited using the Si-containingfilm forming compositions with one or several other precursorscontaining elements selected from As, B, P, Ga, Ge, Sn, Sb, Al, In, or atransition metal precursor, and possibly one or more reactant listedabove. Typical precursors that may be used along with the disclosedSi-containing film forming compositions are selected from the familiesof:

-   -   Metal Halides (for example, TiCl₄, TiI₄, TaCl₅, HfCl₄, ZrCl₄,        AlCl₃, NbF₅, etc.);    -   Alkyls (Al, Ge, Ga, In, Sb, Sn, Zn), such as trimethylaluminum,        diethylzinc, triethylgalium;    -   Hydrides (GeH₄, alanes, etc.);    -   Alkylamides (metals of group IV and V transition metals);    -   Imido group (metals of group V and VI);    -   Alkoxides (metals of group IV, V);    -   Cyclopentadienyls (Ru, Co, Fe, Group IV transition metals,        lanthanides etc.);    -   Carbonyls (ex: Ru, Co, Fe, Ni);    -   Amidinates and guanidinates (ex: Co, Mn, Ni, Cu, Sc, etc.);    -   Beta-diketonates (ex: Sc, Cu, lanthanides);    -   Beta-diketoimines (Cu, Ni, Co, etc.);    -   Bis-trialkylsilylamides (Ni, Co, Fe, etc.);    -   Oxo groups (RuO₄, WOCl₄, PO(OEt)₃, AsO(OEt)₃, etc.);    -   Or heteroleptic molecules having a combination of the above        ligands.

The disclosed Si-containing film forming compositions may also be usedin conjunction with another silicon source, such as a halosilane(possibly selected from SiH₃Cl, SiH₂Cl₂, SiHCl₃, SiCl₄, SiBr₄, SiI₄,SiHI₃, SiH₂I₂, SiH₃I, SiF₄), a polysilane SiH_(x)H_(2x+2), or a cyclicpolysilane SiH_(x)H_(2x), a halo-polysilane (Si_(x)Cl_(2x+2),Si_(x)H_(y)Cl_(2x+2−y), such as HCDS, OCTS, PCDS, MCDS or DCDS, acarbosilane having a Si—(CH₂)_(n)—Si backbone, with n=1 or 2.

Also disclosed are methods of using the disclosed Si-containing filmforming compositions for vapor deposition methods, including various CVDand ALD methods. The disclosed methods provide for the use of thedisclosed Si-containing film forming compositions for deposition ofsilicon-containing films, preferably silicon nitride (SiN) films,silicon-oxide (SiO) films, and nitrogen doped silicon-oxide films. Thedisclosed methods may be useful in the manufacture of semiconductor,photovoltaic, LCD-TFT, flat panel type devices, refractory materials, oraeronautics.

The disclosed methods for forming a silicon-containing layer on asubstrate include: placing a substrate in a reactor, delivering into thereactor a vapor including the Si-containing film forming composition,and contacting the vapor with the substrate (and typically directing thevapor to the substrate) to form a silicon-containing layer on thesurface of the substrate. Alternatively, the substrate is moved to thechamber that contains the precursor vapors (spatial ALD) and then movedto another area that contains the reactant. Other physical treatmentsteps may be carried in between the exposure to precursor and reactants,such as a flash anneal, a UV cure, etc.

The methods may include forming a bimetal-containing layer on asubstrate using the vapor deposition process and, more specifically, fordeposition of SiMO_(x) films wherein x is 4 and M is Ti, Hf, Zr, Ta, Nb,V, Al, Sr, Y, Ba, Ca, As, B, P, Sb, Bi, Sn, lanthanides (such as Er), orcombinations thereof. The disclosed methods may be useful in themanufacture of semiconductor, photovoltaic, LCD-TFT, or flat panel typedevices. An oxygen source, such as O₃, O₂, H₂O, NO, H₂O₂, acetic acid,formalin, para-formaldehyde, alcohol, a diol, oxygen radicals thereof,and combinations thereof, but preferably O₃ or plasma treated O₂, mayalso be introduced into the reactor.

The disclosed Si-containing film forming compositions may be used todeposit silicon-containing films using any deposition methods known tothose of skill in the art. Examples of suitable deposition methodsinclude chemical vapor deposition (CVD) or atomic layer deposition(ALD). Exemplary CVD methods include thermal CVD, pulsed CVD (PCVD), lowpressure CVD (LPCVD), subatmospheric CVD (SACVD) or atmospheric pressureCVD (APCVD), hot-wire CVD (HWCVD, also known as cat-CVD, in which a hotwire serves as an energy source for the deposition process), radicalsincorporated CVD, plasma enhanced CVD (PECVD) including but not limitedto flowable CVD (FCVD), and combinations thereof. Exemplary ALD methodsinclude thermal ALD, plasma enhanced ALD (PEALD), spatial isolation ALD,hot-wire ALD (HWALD), radicals incorporated ALD, and combinationsthereof. Super critical fluid deposition may also be used. Thedeposition method is preferably FCVD, ALD, PE-ALD, or spatial ALD inorder to provide suitable step coverage and film thickness control.

The Si-containing film forming compositions are delivered into a reactorin vapor form by conventional means, such as tubing and/or flow meters.The vapor form of the compositions may be produced by vaporizing theneat or blended composition solution through a conventional vaporizationstep such as direct vaporization, distillation, by bubbling. Thecomposition may be fed in liquid state to a vaporizer where it isvaporized before it is introduced into the reactor. Prior tovaporization, the composition may optionally be mixed with one or moresolvents. The solvents may be selected from the group consisting oftoluene, ethyl benzene, xylene, mesitylene, decane, dodecane, octane,hexane, pentane, or others. The resulting concentration may range fromapproximately 0.05 M to approximately 2 M.

Alternatively, the Si-containing film forming compositions may bevaporized by passing a carrier gas into a container containing theprecursor or by bubbling of the carrier gas into the precursor. Thecomposition may optionally be mixed in the container with one or moresolvents. The solvents may be selected from the group consisting oftoluene, ethyl benzene, xylene, mesitylene, decane, dodecane, octane,hexane, pentane, or others. The resulting concentration may range fromapproximately 0.05 M to approximately 2 M. The carrier gas may include,but is not limited to, Ar, He, or N₂, and mixtures thereof. Bubblingwith a carrier gas may also remove any dissolved oxygen present in theneat or blended composition. The carrier gas and composition are thenintroduced into the reactor as a vapor.

If necessary, the container may be heated to a temperature that permitsthe Si-containing film forming composition to be in liquid phase and tohave a sufficient vapor pressure. The container may be maintained attemperatures in the range of, for example, 0 to 150° C. Those skilled inthe art recognize that the temperature of the container may be adjustedin a known manner to control the amount of composition vaporized. Thetemperature is typically adjusted to reach a vapor pressure of 0.1-100torr, preferably around 1-20 torr.

The vapor of the Si-containing film forming composition is generated andthen introduced into a reaction chamber containing a substrate. Thetemperature and the pressure in the reaction chamber and the temperatureof the substrate are held at conditions suitable for vapor deposition ofat least part of the mono-substituted TSA precursor onto the substrate.In other words, after introduction of the vaporized composition into thereaction chamber, conditions within the reaction chamber are adjustedsuch that at least part of the vaporized precursor is deposited onto thesubstrate to form the Si-containing layer. One of ordinary skill in theart will recognize that “at least part of the vaporized compound isdeposited” means that some or all of the compound reacts with or adheresto the substrate. Herein, a reactant may also be used to help information of the Si-containing layer. Furthermore, the Si-containinglayer may be cured by UV and Electron beam.

The reaction chamber may be any enclosure or chamber of a device inwhich deposition methods take place, such as, without limitation, aparallel-plate type reactor, a cold-wall type reactor, a hot-wall typereactor, a single-wafer reactor, a multi-wafer reactor, or other suchtypes of deposition systems. All of these exemplary reaction chambersare capable of serving as an ALD or CVD reaction chamber. The reactionchamber may be maintained at a pressure ranging from about 0.5 mTorr toabout 20 Torr for all ALD and subatmospheric CVD. Subatmospheric CVD andatmospheric CVD pressures may range up to 760 Torr (atmosphere). Inaddition, the temperature within the reaction chamber may range fromabout 0° C. to about 800° C. One of ordinary skill in the art willrecognize that the temperature may be optimized through mereexperimentation to achieve the desired result.

The temperature of the reactor may be controlled by either controllingthe temperature of the substrate holder or controlling the temperatureof the reactor wall. Devices used to heat the substrate are known in theart. The reactor wall is heated to a sufficient temperature to obtainthe desired film at a sufficient growth rate and with desired physicalstate and composition. A non-limiting exemplary temperature range towhich the reactor wall may be kept from approximately 20° C. toapproximately 800° C. When a plasma deposition process is utilized, thedeposition temperature may range from approximately 0° C. toapproximately 550° C. Alternatively, when a thermal process isperformed, the deposition temperature may range from approximately 200°C. to approximately 800° C.

Alternatively, the substrate may be heated to a sufficient temperatureto obtain the desired silicon-containing film at a sufficient growthrate and with desired physical state and composition. A non-limitingexemplary temperature range to which the substrate may be heatedincludes from 50° C. to 600° C. Preferably, the temperature of thesubstrate remains less than or equal to 500° C.

Alternatively, the ALD process may be carried at a substrate temperaturebeing set below a self-decomposition of the precursor. One of ordinaryskill in the art would recognize how to determine the self-decompositiontemperature of the precursor.

The reactor contains one or more substrates onto which the films will bedeposited. A substrate is generally defined as the material on which aprocess is conducted. The substrates may be any suitable substrate usedin semiconductor, photovoltaic, flat panel, or LCD-TFT devicemanufacturing. Examples of suitable substrates include wafers, such assilicon, silica, glass, plastic or GaAs wafers. The wafer may have oneor more layers of differing materials deposited on it from a previousmanufacturing step. For example, the wafers may include silicon layers(crystalline, amorphous, porous, etc.), silicon oxide layers, siliconnitride layers, silicon oxy nitride layers, carbon doped silicon oxide(SiCOH) layers, photoresist layers, anti-reflective layers, orcombinations thereof. Additionally, the wafers may include copper layersor noble metal layers (e.g. platinum, palladium, rhodium, or gold). Thelayers may include oxides which are used as dielectric materials in MIM,DRAM, STT RAM, PC-RAM or FeRam technologies (e.g., ZrO₂ based materials,HfO₂ based materials, TiO₂ based materials, rare earth oxide basedmaterials, ternary oxide based materials such as strontium rutheniumoxide (SRO), etc.) or from nitride-based films (e.g., TaN) that are usedas an oxygen barrier between copper and the low-k layer. The wafers mayinclude barrier layers, such as manganese, manganese oxide, etc. Plasticlayers, such as poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate)(PEDOT:PSS) may also be used. The layers may be planar or patterned. Forexample, the layer may be a patterned photoresist film made ofhydrogenated carbon, for example CH_(x), wherein x is greater than zero.The disclosed processes may deposit the silicon-containing layerdirectly on the wafer or directly on one or more than one (whenpatterned layers form the substrate) of the layers on top of the wafer.Furthermore, one of ordinary skill in the art will recognize that theterms “film” or “layer” used herein refer to a thickness of somematerial laid on or spread over a surface and that the surface may be atrench or a line. Throughout the specification and claims, the wafer andany associated layers thereon are referred to as substrates. In manyinstances though, the preferred substrate utilized may be selected fromcopper, silicon oxide, photoresist, hydrogenated carbon, TiN, SRO, Ru,and Si type substrates, such as polysilicon or crystalline siliconsubstrates. For example, a silicon nitride film may be deposited onto aSi layer. In subsequent processing, alternating silicon oxide andsilicon nitride layers may be deposited on the silicon nitride layerforming a stack of multiple SiO₂/SiN layers used in 3D NAND gates.Furthermore, the substrate may be coated with patterned or unpatternedorganic or inorganic films.

In addition to the disclosed Si-containing film forming compositions, areactant may also be introduced into the reactor. The reactant may be anoxidizing agent, such as one of O₂, O₃, H₂O, H₂O₂; oxygen containingradicals, such as O⁻ or OH, NO, NO₂; carboxylic acids such as formicacid, acetic acid, propionic acid, radical species of NO, NO₂, or thecarboxylic acids; para-formaldehyde; and mixtures thereof. Preferably,the oxidizing agent is selected from the group consisting of O₂, O₃, H₂,H₂O₂, oxygen containing radicals thereof such as O or OH, and mixturesthereof. Preferably, when an ALD process is performed, the reactant isplasma treated oxygen, ozone, or combinations thereof. When an oxidizingagent is used, the resulting silicon containing film will also containoxygen.

Alternatively, the reactant may be a nitrogen-containing reactant, suchas one of N₂, NH₃, hydrazines (for example, N₂H₄, MeHNNH₂, MeHNNHMe),organic amines (for example, N(CH₃)H₂, N(C₂H₅)H₂, N(CH₃)₂H, N(C₂H₅)₂H,N(CH₃)₃, N(C₂H₅)₃, (SiMe₃)₂NH), pyrazoline, pyridine, diamine (such asethylene diamine), radicals thereof, or mixtures thereof. When anN-containing source agent is used, the resulting silicon containing filmwill also contain nitrogen.

When a reducing agent is used, such as H₂, H radicals, but also otherH-containing gases and precursors such as metal and metalloid hydrides,the resulting silicon containing film may be pure Si.

The reactant may be treated by plasma, in order to decompose thereactant into its radical form. N₂ may also be utilized when treatedwith plasma. For instance, the plasma may be generated with a powerranging from about 50 W to about 2000 W, preferably from about 100 W toabout 500 W. The plasma may be generated or present within the reactoritself. Alternatively, the plasma may generally be at a location removedfrom the reactor, for instance, in a remotely located plasma system. Oneof skill in the art will recognize methods and apparatus suitable forsuch plasma treatment.

The Si-containing film forming compositions may also be used with ahalosilane or polyhalodisilane, such as hexachlorodisilane,pentachlorodisilane, or tetrachlorodisilane, and one or more reactantsto form Si, SiCN, or SiCOH films. PCT Publication Number WO2011/123792discloses a SiN layer (not a Si or SiCOH layer), and the entire contentsof which are incorporated herein in their entireties.

When the desired silicon-containing film also contains another element,such as, for example and without limitation, Ti, Hf, Zr, Ta, Nb, V, Al,Sr, Y, Ba, Ca, As, B, P, Sb, Bi, Sn, Ge lanthanides (such as Er), orcombinations thereof, another precursor may include a metal-containingprecursor which is selected from, but not limited to:

-   -   Metal Halides (e.g., TiCl₃, TiI₄, TaCl₅, HfCl₄, ZrCl₄, AlCl₃,        NbF₅, etc.);    -   Alkyls (Al, Ge, Ga, In, Sb, Sn, Zn), such as trimethylaluminum,        diethylzinc, triethylgalium;    -   Hydrides (GeH₄, alanes, etc.);    -   Alkylamides (metals of group IV and V transition metals);    -   Imido group (metals of group V and VI);    -   Alkoxides (metals of group IV, V);    -   Cyclopentadienyls (Ru, Co, Fe, Group IV transition metals,        lanthanides, etc.);    -   Carbonyls (ex: Ru, Co, Fe, Ni);    -   Amidinates and guanidinates (ex: Co, Mn, Ni, Cu, Sc, etc.);    -   Beta-diketonates (e.g.: Sc, Cu, lanthanides);    -   Beta-diketoimines (Cu, Ni, Co, etc.);    -   Bis-trialkylsilylamides (Ni, Co, Fe, etc.);    -   Oxo groups (RuO₄, WOCl₄, PO(OEt)₃, AsO(OEt)₃, etc.);    -   Heteroleptic molecules having a mixed set of ligands selected        from the above families.

The Si-containing film forming compositions and one or more reactantsmay be introduced into the reaction chamber simultaneously (e.g., CVD),sequentially (e.g., ALD), or in other combinations. For example, theSi-containing film forming composition may be introduced in one pulseand two additional metal sources may be introduced together in aseparate pulse (e.g., modified ALD). Alternatively, the reaction chambermay already contain the reactant prior to introduction of theSi-containing film forming composition. The reactant may be passedthrough a plasma system localized or remotely from the reaction chamber,and decomposed to radicals. Alternatively, the Si-containing filmforming composition may be introduced to the reaction chambercontinuously while other metal sources are introduced by pulse (e.g.,pulsed-CVD). In each example, a pulse may be followed by a purge orevacuation step to remove excess amounts of the component introduced. Ineach example, the pulse may last for a time period ranging from about0.01 s to about 20 s, alternatively from about 0.3 s to about 3 s,alternatively from about 0.5 s to about 2 s. In another alternative, theSi-containing film forming composition and one or more reactants may besimultaneously sprayed from a shower head under which a susceptorholding several wafers is spun (e.g., spatial ALD).

In a non-limiting exemplary ALD type process, the vapor phase of theSi-containing film forming composition is introduced into the reactionchamber, where it is contacted with a suitable substrate and forms asilicon-containing layer on the substrate. Excess composition may thenbe removed from the reaction chamber by purging and/or evacuating thereaction chamber. An oxygen source is introduced into the reactionchamber where it reacts with the silicon-containing layer in aself-limiting manner. Any excess oxygen source is removed from thereaction chamber by purging and/or evacuating the reaction chamber. Ifthe desired film is a silicon oxide film, this two-step process mayprovide the desired film thickness or may be repeated until a filmhaving the necessary thickness has been obtained.

Alternatively, if the desired film is a silicon metal oxide film (i.e.,SiMO_(x), wherein x may be 4 and M is Ti, Hf, Zr, Ta, Nb, V, Al, Sr, Y,Ba, Ca, As, B, P, Sb, Bi, Sn, Ge, lanthanides (such as Er), orcombinations thereof), the two-step process above may be followed byintroduction of a second vapor of a metal-containing precursor into thereaction chamber. The metal-containing precursor will be selected basedon the nature of the silicon metal oxide film being deposited. Afterintroduction into the reaction chamber, the metal-containing precursoris contacted with the silicon oxide layer on the substrate. Any excessmetal-containing precursor is removed from the reaction chamber bypurging and/or evacuating the reaction chamber. Once again, an oxygensource may be introduced into the reaction chamber to react with themetal-containing precursor. Excess oxygen source is removed from thereaction chamber by purging and/or evacuating the reaction chamber. If adesired film thickness has been achieved, the process may be terminated.However, if a thicker film is desired, the entire four-step process maybe repeated. By alternating the provision of the Si-containing filmforming compositions, metal-containing precursor, and oxygen source, afilm of desired composition and thickness may be deposited.

Additionally, by varying the number of pulses, films having a desiredstoichiometric M:Si ratio may be obtained. For example, a SiMO₂ film maybe obtained by having one pulse of the mono-substituted TSA precursorand one pulses of the metal-containing precursor, with each pulse beingfollowed by pulses of the oxygen source. However, one of ordinary skillin the art will recognize that the number of pulses required to obtainthe desired film may not be identical to the stoichiometric ratio of theresulting film.

In a non-limiting exemplary PE-ALD type process, the vapor phase of theSi-containing film forming composition is introduced into the reactionchamber, where it is contacted with a suitable substrate, while a lowreactivity oxygen source, such as O₂, is continuously flowing to thechamber. Excess composition may then be removed from the reactionchamber by purging and/or evacuating the reaction chamber. A plasma isthen lit to activate the oxygen source to react with the absorbedmono-substituted TSA precursor in a self-limiting manner. The plasma isthen switched off and the flow of the Si-containing film formingcomposition may proceed immediately after. This two-step process mayprovide the desired film thickness or may be repeated until a siliconoxide film having the necessary thickness has been obtained. The siliconoxide film may contain some C impurities, typically between 0.005% and2%. The oxygen gas source and the substrate temperature may be selectedby one of ordinary skill in the art so as to prevent reaction betweenthe oxygen source and the mono-substituted TSA when the plasma is off.Dialkylamino-substituted TSA are particularly suitable for such aprocess, and are preferably (SiH₃)₂N—SiH₂-NEt₂, (SiH₃)₂N—SiH₂—NiPr₂ or(SiH₃)₂N—SiH₂—NHR, R being -tBu or —SiMe₃.

In another non-limiting exemplary PE-ALD type process, the vapor phaseof the Si-containing film forming compositions is introduced into thereaction chamber, where it is contacted with a suitable substrate, whilea low reactivity nitrogen source, such as N₂, is continuously flowing tothe chamber. Excess composition may then be removed from the reactionchamber by purging and/or evacuating the reaction chamber. A plasma isthen lit to activate the nitrogen source to react with the absorbedmono-substituted TSA precursor in a self-limiting manner. The plasma isthen switched off and flow of the Si-containing film forming compositionmay proceed immediately after. This two-step process may provide thedesired film thickness or may be repeated until a silicon nitride filmhaving the necessary thickness has been obtained. The silicon nitridefilm may contain some C impurities, typically between 0.5% and 10%. Thenitrogen gas source and the substrate temperature may be selected by oneof ordinary skill in the art so as to prevent reaction between thenitrogen source and the mono-substituted TSA when the plasma is off.Amino-substituted TSA and mono-halo TSA are particularly suitable forsuch a process, and are preferably (SiH₃)₂N—SiH₂—Cl, (SiH₃)₂N—SiH₂-NEt₂,(SiH₃)₂N—SiH₂—NiPr₂, (SiH₃)₂N—SiH₂—NHR, R being -tBu or —SiMe₃, or(SiH₃)₂N—SiH₂—N(SiH₃)₂.

In a non-limiting exemplary LPCVD type process, the vapor phase of theSi-containing film forming compositions, preferably containing amono-halo substituted TSA precursor, is introduced into the reactionchamber holding the substrates and kept at a pressure typically between0.1 and 10 torr, and more preferably between 0.3 and 3 torr, and at atemperature between 250° C. and 800° C., preferably between 350° C. and600° C., where it is mixed with a reactant, typically NH₃. A thinconformal SiN film may thus be deposited on the substrate(s). One ofordinary skill in the art will recognize that the Si/N ratio in the filmmay be tuned by adjusting the mono-substituted TSA precursor andN-source flow rates.

In another alternative, dense SiN films may be deposited using an ALDmethod with hexachlorodisilane (HCDS), pentachlorodisilane (PCDS),monochlorodisilane (MCDS), dichlorodisilane (DCDS) or monochlorosilane(MCS), the disclosed Si-containing film forming compositions, and anammonia reactant. The reaction chamber may be controlled at 5 Torr, 550°C., with a 55 sccm continuous flow of Ar. An approximately 10 secondlong pulse of the disclosed Si-containing film forming composition at aflow rate of approximately 1 sccm is introduced into the reactionchamber. The composition is purged from the reaction chamber with anapproximately 55 sccm flow of Ar for approximately 30 seconds. Anapproximately 10 second pulse of HCDS at a flow rate of approximately 1sccm is introduced into the reaction chamber. The HCDS is purged fromthe reaction chamber with an approximately 55 sccm flow of Ar forapproximately 30 seconds. An approximately 10 second long pulse of NH₃at a flow rate of approximately 50 sccm is introduced into the reactionchamber. The NH₃ is purged from the reaction chamber with anapproximately 55 sccm flow of Ar for approximately 10 seconds. These 6steps are repeated until the deposited layer achieves a suitablethickness. One of ordinary skill in the art will recognize that theintroductory pulses may be simultaneous when using a spatial ALD device.As described in PCT Pub No WO2011/123792, the order of the introductionof the precursors may be varied and the deposition may be performed withor without the NH₃ reactant in order to tune the amounts of carbon andnitrogen in the SiCN film. One of ordinary skill in the art wouldfurther recognize that the flow rates and pulse times may vary amongstdifferent deposition chambers and would be able to determine thenecessary parameter for each device.

In a non-limiting exemplary process, the vapor phase of the disclosedSi-containing film forming compositions, preferably containing mono-halosubstituted TSA, is introduced into the reaction chamber holding asubstrate having a porous low-k film. A pore sealing film may bedeposited in the conditions described in US 2015/0004806 (i.e., byintroducing the disclosed silicon-containing film forming composition,an oxidant (such as ozone, hydrogen peroxide, oxygen, water, methanol,ethanol, isopropanol, nitric oxide, nitrous dioxide, nitrous oxide,carbon monoxide, or carbon dioxide), and a halogen free catalystcompound (such as nitric acid, phosphoric acid, sulfuric acid,ethylenediaminetetraacetic acid, picric acid, or acetic acid) to areaction chamber and exposing the substrate to the process gases underconditions such that a condensed flowable film forms on the substrate).

In yet another alternative, a silicon-containing film may be depositedby the flowable PECVD method disclosed in U.S. Patent ApplicationPublication No. 2014/0051264 using the disclosed compositions and aradical nitrogen- or oxygen-containing reactant. The radical nitrogen-or oxygen-containing reactant, such as NH₃ or H₂O respectively, isgenerated in a remote plasma system. The radical reactant and the vaporphase of the disclosed precursors are introduced into the reactionchamber where they react and deposit the initially flowable film on thesubstrate. Applicants believe that the nitrogen atoms of the(SiH₃)₂N—(SiH₂—X) structure helps to further improve the flowability ofthe deposited film, resulting in films having less voids, especiallywhen X is an amino group, and more specifically when X is a disilylaminogroup like —N(SiH₃)₂.

The silicon-containing films resulting from the processes discussedabove may include SiO₂, nitrogen doped silicon oxide, SiN, SiON, SiCN,SiCOH, or MSiN_(y)O_(x), wherein M is an element such as Ti, Hf, Zr, Ta,Nb, V, Al, Sr, Y, Ba, Ca, As, B, P, Sb, Bi, Sn, Ge, and x, y may be from0-4 and y+x=4, depending of course on the oxidation state of M. One ofordinary skill in the art will recognize that by judicial selection ofthe appropriate mono-substituted TSA precursor and reactants, thedesired film composition may be obtained.

Upon obtaining a desired film thickness, the film may be subject tofurther processing, such as thermal annealing, furnace-annealing, rapidthermal annealing, UV or e-beam curing, and/or plasma gas exposure.Those skilled in the art recognize the systems and methods utilized toperform these additional processing steps. For example, thesilicon-containing film may be exposed to a temperature ranging fromapproximately 200° C. and approximately 1000° C. for a time ranging fromapproximately 0.1 second to approximately 7200 seconds under an inertatmosphere, a H-containing atmosphere, a N-containing atmosphere, anO-containing atmosphere, or combinations thereof. Most preferably, thetemperature is 600° C. for less than 3600 seconds under a reactiveH-containing atmosphere. The resulting film may contain fewer impuritiesand therefore may have improved performance characteristics. Theannealing step may be performed in the same reaction chamber in whichthe deposition process is performed. When the deposition process is aFCVD, the curing step is preferably an oxygen curing step, carried outat a temperature lower than 600° C. The oxygen containing atmosphere maycontain H₂O or O₃. Alternatively, the substrate may be removed from thereaction chamber, with the annealing/flash annealing process beingperformed in a separate apparatus.

EXAMPLES

The following non-limiting examples are provided to further illustrateembodiments of the invention. However, the examples are not intended tobe all inclusive and are not intended to limit the scope of theinventions described herein.

The examples described herein are TSA based precursors, i.e.,mono-substituted TSA.

Example 1: Synthesis of (SiH₃)₂N—SiH₂—NiPr₂ and of (SiH₃)₂N—SiH₂-NEt₂

300 g of diisopropylamine (3.0 mol) was charged to a 1-liter filterflask equipped with an overhead mechanical stirrer, a nitrogen bubbler,a chiller and a hydride scrubber as a reactor. 60 g (0.4 mol) ofchlorotrisilylamine was charged to a dropping funnel. The droppingfunnel was affixed to the reactor. A nitrogen sweep was added to thedropping funnel to prevent salt formation in the tip of the funnel. Thechiller was set to 18° C. and the chlorotrisilylamine was added viadropping funnel over a 1.5 hr period. The reactor temperature was set at22-23° C. during the addition. The reactor was allowed to stir for 0.5hr after the addition was complete.

The amine hydrochloride salt was then filtered. The filter cake wasrinsed with two 50 ml aliquots of diisopropylamine. The majority of thediisopropylamine was distilled off leaving 72 g of a crude product. Thecrude product was combined with other crude products from severalsmaller scale preparations of (SiH₃)₂N—SiH₂—NiPr₂ done in a similarfashion. (SiH₃)₂N—SiH₂—NiPr₂ was then distilled at 86° C. under a vacuumof −28 inches of mercury and 79 g of >99% pure product was collected.The overall yield was 56%. Table 2 shows vapor pressure data of(SiH₃)₂N—SiH₂—NiPr₂ estimated from the distillation and TSU data.

TABLE 2 Vapor pressure data of (SiH₃)₂N—SiH₂—NiPr₂ Temperature (° C.)Pressure (torr) 86 38 100 72 150 140

The synthesis of (SiH₃)₂N—SiH₂-NEt₂ proceeds similarly with the samemolar ratio, but replaces diisopropylamine with diethylamine.

Example 2: Synthesis of (SiH₃)₂N—SiH₂—NHiPr

300 g of isopropylamine (3.0 mol) was charged to a 1-liter filter flaskequipped with an overhead mechanical stirrer, a nitrogen bubbler, achiller and a hydride scrubber as a reactor. 60 g (0.4 mol) ofchlorotrisilylamine was charged to a dropping funnel. The droppingfunnel was affixed to the reactor. A nitrogen sweep was added to thedropping funnel to prevent salt formation in the tip of the funnel. Thechiller was set to 18° C. and the chlorotrisilylamine was added viadropping funnel over a 1.5 hr period. The reactor temperature was set at22-23° C. during the addition. The reactor was allowed to stir for 0.5hr after the addition was complete. The amine hydrochloride salt wasthen filtered. The filter cake was rinsed with two 50 mL aliquots ofisopropylamine. The majority of the isopropylamine was distilled offleaving 72 g of a crude product. The crude product was combined withother crude products from several smaller scale preparations of(SiH₃)₂N—SiH₂—NHiPr done in a similar fashion. (SiH₃)₂N—SiH₂—NHiPr wasthen distilled at 86° C. under a vacuum of −28 inches of mercury and 79g of >99% pure product was collected.

Example 3: Synthesis of (SiH₃)₂N—SiH₂—Br and of (SiH₃)₂N—SiH₂—N(SiH₃)₂

(SiH₃)₂N—SiH₂—Br and (SiH₃)₂N—SiH₂—N(SiH₃)₂ may be obtained by SnBr₄reacts with TSA:SnBr₄+H₃SiN(SiH₃)₂═BrH₂SiN(SiH₃)₂+(SiH₃)₂N—SiH₂—N(SiH₃)₂+SnBr₂+HBr. Aside product of the above reaction, HBr, may then be removed by areaction with the starting material TSA, i.e.,N(SiH₃)₃+4HBr=NH₄Br+3BrSiH₃. The synthesis process is as follows.

A round bottom flask with a PTFE-coated magnetic stir egg was chargedwith stoichiometric excess of TSA. If necessary, a solvent (e.g.,dodecane) and an HBr scavenger (e.g., tributylamine) may be added to theflask prior to adding TSA. The flask was fitted with a cold fingercondenser or a distillation head. A liquid addition funnel was attachedto the flask and charged with a solution of SnBr₄ in a solvent (such as,anisole or dodecane). The flask may then be cooled down and the SnBr₄solution was added dropwise to the flask. The headspace of the flask maybe kept under atmospheric pressure of nitrogen or at a reduced pressurein order to remove HBr as it forms.

After the addition was finished, the volatile products may be collectedby pulling vacuum through trap(s). The collected volatile products maythen be analyzed by GCMS. It was found that (SiH₃)₂N(SiH₂Br) and(SiH₃)₂N(SiH₂N(SiH₃)₂) were formed upon treating TSA with SnBr₄. Thefollowing byproducts were also identified: silane, bromosilane,dibromotrisilylamine. The solvents and unreacted SnBr₄ (in some cases)were also found.

The resulting (SiH₃)₂N—SiH₂—N(SiH₃)₂ was liquid at room temperature(˜22° C.), with a melting point of approximately −106° C. and a boilingpoint of approximately 131° C. The vapor pressure was calculated to be˜8 hPa at 27° C.

Example 4

The following PEALD testing was performed using a Picosun R200 PEALD 8″deposition tool with a 4″ wafer. The vapor of the mono-substituted TSAprecursor was delivered to the Picosun tool as shown in FIG. 1 .

ALD tests were performed using the (SiH₃)₂N—SiH₂—NiPr₂, which was placedin an ampoule heated to 70° C. and O₂ plasma as oxidizing reactant.Typical ALD conditions were used with the reactor pressure fixed at −9hPa (1 hPa=100 Pa=1 mbar). Two 0.1-second pulses of the precursor vaporwere introduced into the deposition chamber via overpressure in theampoule using the 3-way pneumatic valve. The 0.1-second pulses wereseparated by a 0.5 second pause. A4-second N2 purge removed any excessprecursor. A 16-second plasma O₂ pulse was followed by a 3-second N2purge. The process was repeated until a minimum thickness of 300Angstrom was obtained. Depositions were performed with the substrateheated to 70° C., 150° C., and 300° C. Real self limited ALD growthbehavior was validated as shown in FIG. 2 by increasing the number ofprecursor pulses within a given cycle.

ALD tests were also performed using the prior art SiH₂(NEt₂)₂ precursor,which was placed in an ampoule heated to 60° C. and O₂ plasma asoxidizing reactant. Applicants believe that SiH₂(NEt₂)₂ is currentlyused to deposit SiO₂ in several commercial processes. Typical ALDconditions were used with the reactor pressure fixed at ˜9 hPa (1hPa=100 Pa=1 mbar). Two 0.1-second pulses of the precursor vapor wereintroduced into the deposition chamber via overpressure in the ampouleusing the 3-way pneumatic valve. The 0.1-second pulses were separated bya 0.5 second pause. A4-second N₂ purge removed any excess precursor.A16-second plasma O₂ pulse was followed by a 3-second N₂ purge. Theprocess was repeated until a minimum thickness of 300 Ang was reached.Depositions were performed at 70° C., 150° C., 200° C., and 300° C. Asshown in FIG. 3 , the growth per cycle decreased with increasingtemperature.

TABLE 3 summarizes the results: (SiH₃)₂N— SiH₂(NEt₂)₂ SiH₂—NiPr₂ Growthrate 70° C.¹ 1.42 Ang/cycle 3.10 Ang/cycle Growth rate 300° C.¹ 0.98Ang/cycle 2.05 Ang/cycle Wet Etch Rate 70° C.² 9.4 Ang/sec 8.8 Ang/secWet Etch Rate 150° C.² 7.2 Ang/sec 6.7 Ang/sec Wet Etch Rate 300° C.²6.6 Ang/sec 6.7 Ang/sec Refractive Index 70° C.³ 1.432 1.460 Atomic %Carbon 70° C.⁴  0.05% TBD Atomic % Carbon 150° C.⁴ 0.045% 0.015-0.03%Atomic % Hydrogen 150° C.⁴    ~10%     −10%   Atomic % Nitrogen 150° C.⁴0.015%  0.1% Within Wafer Non  2.84% 2.90% Uniformity⁵ ¹Growth rate forfilms deposited at the stated temperatures ²Wet Etch Rate for filmsdeposited at the stated temperatures ³Refractive index for filmdeposited at 70° C. ⁴Atomic percentage in a film deposited at the statedtemperature as determined by Secondary Ion Mass Spectrometry (SIMS).Hydrogen content is subject to uncertainty when measured by SIMS, as oneskilled in the art would recognize. ⁵Within Wafer Non Uniformity of afilm deposited at 200° C. as determined by ellipsometer over a 6 inchsilicon wafer. This parameter was not optimized and better uniformitywould be expected from an industrial tool.

As can be seen, the growth rate for films produced by(SiH₃)₂N—SiH₂—NiPr₂ is much better than those of SiH₂(NEt₂)₂ at both 70°C. and 300° C. At 70° C., (SiH₃)₂N—SiH₂—NiPr₂ has a much better wet etchrate and refractive index than SiH₂(NEt₂)₂. which both indicateformation of a much better, denser oxide film.

Example 5

ALD tests to deposit N-doped silicon oxide were performed using the(SiH₃)₂N—SiH₂—NiPr₂, which was placed in an ampoule heated to 70° C., 02plasma as oxidizing reactant and NH₃ plasma as an additional reactant.Typical ALD conditions were used with the reactor pressure fixed at ˜9hPa. Two 0.1-second pulses of the precursor vapor were introduced intothe deposition chamber via overpressure in the ampoule using the 3-waypneumatic valve. The 0.1-second pulses were separated by a 0.5 secondpause. A 4-second N₂ purge removed any excess precursor. A 16-secondplasma O₂ pulse was followed by a 3-second N₂ purge. Two 0.1-secondpulses of the precursor vapor were introduced into the depositionchamber via overpressure in the ampoule using the 3-way pneumatic valve.The 0.1-second pulses were separated by a 0.5 second pause. A 4-secondN₂ purge removed any excess precursor. An 11-second plasma NH₃ pulse wasfollowed by a 3-second purge. The entire process (precursor—plasmaO₂—precursor—plasma NH₃) was repeated until the thickness reached atleast 300 Ang. Depositions were performed at 150° C.

The resulting SiO₂ film had a wet etch rate of 3.2 Ang/sec and Nconcentration of ˜1%. Such a low etch rate is found to be beneficial forspacer-based double patterning to enable a low edge roughness in thetransfer layer when the ALD-deposited silicon oxide film is used as amask. The person ordinary skilled in the art would recognize that theOxygen to Nitrogen content in the obtained film can be tuned byadjusting the number, sequence or/and duration of the O containingreactant and N containing reactant pulses. Applicant believes that a Nconcentration of approximately 0.5% to approximately 5% in an SiO₂ filmis beneficial for the spacer-defined patterning applications.

Example 6

ALD tests were performed using the (SiH₃)₂N—SiH₂—N(SiH₃)₂, which wasplaced in an ampoule heated to 26° C. and O₂ plasma as oxidizingreactant. Typical ALD conditions were used with the reactor pressurefixed at ˜9 hPa. Three 0.1-second pulses of the precursor vapor wereintroduced into the deposition chamber via overpressure in the ampouleusing the 3-way pneumatic valve. The 0.1-second pulses were separated bya 0.5 second pause. A 4-second N₂ purge removed any excess precursor. A16-second plasma O₂ pulse was followed by a 3-second N₂ purge. Theentire process (precursor—plasma O₂—) was repeated until the thicknessreached at least 300 Ang. As shown in FIG. 4 , the growth per cycleincreased with increasing deposition temperatures from 150° C. to 300°C. FIG. 4 also shows comparative growth per cycle results of five0.1-second pulses versus three 0.1-second pulses. Both wereapproximately 0.6 A/cycle, indicating true ALD saturation because thelarger amounts of precursor introduced via 5 pulses do not result in ahigher growth rate than the film produced by 3 pulses.

The growth rate was approximately 0.58 Ang/cycle at 150° C. and resultedin a film having a refractive index of 1.45. For comparison, attempts togrow an SiO₂ film by ALD using pure TSA in similar conditions have notyielded any films, thus proving the benefit of the chemicalfunctionalization to enhance the reactivity with the surface hydroxylgroups.

While embodiments of this invention have been shown and described,modifications thereof may be made by one skilled in the art withoutdeparting from the spirit or teaching of this invention. The embodimentsdescribed herein are exemplary only and not limiting. Many variationsand modifications of the composition and method are possible and withinthe scope of the invention. Accordingly the scope of protection is notlimited to the embodiments described herein, but is only limited by theclaims which follow, the scope of which shall include all equivalents ofthe subject matter of the claims.

What is claimed is:
 1. An atomic layer deposition (ALD) silicon metal oxide film formation process, the process comprising depositing a silicon metal oxide film on a substrate by the steps of: a) a step of sequentially introducing a vapor of a mono-substituted trisilylamine (TSA) precursor and an oxygen-containing reactant into a reactor containing the substrate, the mono-substituted TSA precursor having a formula (SiH₃)₂N—SiH₂—X, wherein X is selected from (i) a halogen atom selected from Cl, Br or I; (ii) an isocyanato group [—NCO]; (iii) an amino group [—NR¹ R²]; (iv) an N-containing C₄-C₁₀ saturated or unsaturated heterocycle; or (v) an alkoxy group [—O—R], and wherein R¹, R² and R each is selected from (x) H; (y) a C₁-C₆ linear or branched, saturated or unsaturated hydrocarbyl group; or (z) a silyl group [SiR′₃] with each R′ being independently selected from H; a halogen atom selected from Cl, Br, I; a Ci-C₄ saturated or unsaturated hydrocarbyl group; a C₁-C₄ saturated or unsaturated alkoxy group; or an amino group [—NR³R⁴] with each R³ and R⁴ being selected from H or a C₁-C₆ linear or branched, saturated or unsaturated hydrocarbyl group; and further provided that if R¹═H, then R²≠H or Me, and b) a step of introducing a vapor of a metal containing second precursor.
 2. The ALD silicon metal oxide film formation process of claim 1, wherein the oxygen-containing reactant is selected from the group consisting of O₂, O₃, H₂O, H₂O₂, NO, NO₂, N₂O, alcohols, diols, carboxylic acids, ketones, ethers, O atoms, O radicals, O ions, and combinations thereof.
 3. The ALD silicon metal oxide film formation process of claim 2, wherein the oxygen-containing reactant is plasma O₂.
 4. The ALD silicon metal oxide film formation process of claim 1, wherein X is Cl, Br, or I.
 5. The ALD silicon metal oxide film formation process of claim 2, wherein X is Cl, Br, or I.
 6. The ALD silicon metal oxide film formation process of claim 3, wherein X is Cl, Br, or I.
 7. The ALD silicon metal oxide film formation process of claim 1, wherein X is Cl.
 8. The ALD silicon metal oxide film formation process of claim 2, wherein X is Cl.
 9. The ALD silicon metal oxide film formation process of claim 3, wherein X is Cl.
 10. The ALD silicon metal oxide film formation process of claim 1, wherein X is wherein X is NiPr₂ or NEt₂.
 11. The ALD silicon metal oxide film formation process of claim 2, wherein X is wherein X is NiPr₂ or NEt₂.
 12. The ALD silicon metal oxide film formation process of claim 3, wherein X is wherein X is NiPr₂ or NEt₂.
 13. The ALD silicon metal oxide film formation process of claim 1, wherein the metal of the second precursor is selected from the group consisting of group 2, group 13, group 14, transition metal, lanthanides, and combinations thereof.
 14. The ALD silicon metal oxide film formation process of claim 2, wherein the metal of the second precursor is selected from the group consisting of group 2, group 13, group 14, transition metal, lanthanides, and combinations thereof.
 15. The ALD silicon metal oxide film formation process of claim 3, wherein the metal of the second precursor is selected from the group consisting of group 2, group 13, group 14, transition metal, lanthanides, and combinations thereof.
 16. The ALD silicon metal oxide film formation process of claim 1, wherein the metal of the second precursor is selected from the group consisting of Ti, Hf, Zr, Ta, Nb, V, Al, Sr, Y, Ba, Ca, As, B, P, Sb, Bi, Sn, Ge, and combinations thereof.
 17. The ALD silicon metal oxide film formation process of claim 2, wherein the metal of the second precursor is selected from the group consisting of Ti, Hf, Zr, Ta, Nb, V, Al, Sr, Y, Ba, Ca, As, B, P, Sb, Bi, Sn, Ge, and combinations thereof.
 18. The ALD silicon metal oxide film formation process of claim 3, wherein the metal of the second precursor is selected from the group consisting of Ti, Hf, Zr, Ta, Nb, V, Al, Sr, Y, Ba, Ca, As, B, P, Sb, Bi, Sn, Ge, and combinations thereof. 